Audio mixers incorporating voltage control amplifiers (VCAs) are, per se, well known. The output of the VCAs, however, experience some distortion. While some attempts have been made to eliminate or minimize this distortion by using a potentiometer that trims for minimum distortion, these attempts have various drawbacks. For example, if a mixing apparatus has 20 VCAs, 20 trimming potentiometers may be necessary. This is very expensive and additionally may add a great deal of labor and cost to the manufacturing process, especially if the potentiometers must be manually adjusted to trim for minimum distortion.